Labview NXG Web : Vireo doesn't seems to load in Light Browser Anymore

[Joannick_DAM]

Hello all,

So I'm using Labview NXG to develop a Web-Based Application. 

Since it devellopement is very fast, I keep testing newer version but I don't migrate much (since it would take al lot of my time).

Latests version introduced a lot of new things, so I finally decided to move from NXG 2.x beta to NXG4 stable.

Until now vireo (the web Runtime of Labview NXG) worked great on all device and browser, but since the last NXG version, it won't load in "light browser" on android, browser designed to be always open, on full screen, for kiosk, domotic hub, presentation panel and such. It works fine on Chrome/Chromium/FireFox, but won't load in FullScreenBrowser/FullyKioskBrowser and suchs. Thoses browser integrate (theorically) all the javascript and html behavior of full browser, so I'm a little lost here. Is there any reason this does not work anymore ? Is it a bug or a known issue ? I think it may have something to do with Android System Webview but I'm not a web expert...

It is not really new, I observe the same behavior when compiling with NXG 3.1.0

Thanks in advance if you have any idea !

[MilanR · Accepted solution]

Hi Joannick_DAM,

Newer versions of NXG Web Module do rely on newer features only available in modern browsers and a particularly big change that happened in NXG 3.1 is that WebVIs started using the standard cross-browser WebAssembly technology. There are many other modern browser features we use as well that can impact how a WebVI runs and you have likely seen from the NXG 4.0 Web Module System Requirements that the supported browsers are the latest versions of Chrome, Firefox, Edge, and Safari.

I am not familiar with the browsers you have mentioned but it is possible that they are using WebView for Android and one thing to consider is that only in Android 5 (Lollipop) and up does the WebView use an auto-updating modern version of Chromium. Older versions of Android have the version tied to what ships in the operating system. Additionally, we don't specifically test against Android WebView and the Android WebView docs state "for the most part, features that work in Chrome for Android should work in the new WebView" so it seems like WebVIs could run correctly in these unsupported environments but you would have to test your WebVIs to be sure.

The caniuse.com table for WebAssembly will tell you which browsers support the WebAssembly technology and may give a rough idea of what browsers could potentially run WebVIs beyond what is supported. It's also possible those custom browsers are not using the built-in Android WebView and rely on some other technology.

If you already are using modern versions of Android and up to date WebViews, since WebVIs are built on standard cross platform browser technologies you may want to contact those browser vendors with a sample built WebVI to see if they know why the browsers are unable to run the WebVIs.

[Joannick_DAM]

Thank you Milan, that is the answer I was waiting.

I did contacted the develloper of the browser I'm using, and he pointed me in the right direction.

Basically, I'm using a tablet with an old implementtion of Android (6), and on this version, the Webview component version is hardcoded during the OS compilation. Even when I update it, it will still use the saved old version for internal webview. This is probably for security measure (breaking that or getting infected would lead to a system very difficult to fix/use).

The only solutions at my disposal are : 1) root my tablet and use a module to change the Webview version/source used 2) root my tablet and modifiy those values by hand 3) update my tablet to Android 7 or higher or finally 4) change my tablet.

Thank you for your fast answer.